1. Field of the Invention
The present invention relates generally to a probe device of a probe card and more particularly, to a probe seat of a vertical probe device.
2. Description of the Related Art
Upon testing semiconductor chips, a testing equipment is electrically connected with devices under test (hereinafter referred to as the “DUTs”) through a probe card, so that the testing equipment can obtain the testing results of the DUTs by means of signal transmission and analysis. The conventional probe card is usually composed of a circuit board and a probe device, or further includes a space transformer disposed between the circuit board and the probe device. The conventional vertical probe device usually includes a probe seat, and a plurality of vertical probes penetrating through the probe seat in substantially vertical posture. The vertical probes, such as pogo pins, are arranged corresponding in positions to contact pads of the DUTs, so that the contact pads can be probed by the vertical probes at the same time.
The aforesaid probe seat of the vertical probe device usually includes upper, middle and lower dies piled on one another in order. Each of the upper and lower dies has a plurality of probe holes. The middle die is disposed between the upper and lower dies and has a hollow configuration; this means the middle die is provided at the center thereof with a through trough. The probe holes of the upper die communicate with the probe holes of the lower die through the through trough. Each of the vertical probes is inserted through the probe hole of the upper die, the through trough of the middle die and the probe hole of the lower die, and has a bottom end extending out of the lower die for probing the contact pad of the DUT.
If the DUT has numerous contact pads crowded together, the probe device should be correspondingly provided with numerous probes crowded together as well. In particular, if the probe device is a multi-DUT probe head capable of testing a plurality of DUTs at the same time, it has even more probes. However, the hollow-shaped middle die brings the probe seat relatively lower rigidity and provides space enabling the upper and lower dies to be deformed elastically. Therefore, when the numerous probes disposed in the probe seat do the probing action at the same time, the reaction force is liable to bend the probe seat. Especially for the probe seat of the multi-DUT probe head, the dies thereof are large, and the through trough of the middle die thereof is also large. Besides, the multi-DUT probe head receives a relatively larger reaction force because of having relatively more probes. Therefore, the probe seat of the multi-DUT probe head is relatively more liable to be bent.